Air compressor for dental and other purposes



Dec. 18, 1928.

J. E. REID AIR COMPRESSOR FOR DENTAL AND OTHER PURPOSES Filed NOV. 11, 1926 2 Sheets-Sheet 1 James E. E l J Dec. 18, 1928. 1,696,013

J. E. REID AIR COMPRESSOR FOR DENTAL AND OTHER PURPOSES Filed. Nov. 11, 1926 2 Sheets-Sheet 2 Patented Dec. 18, 1928.

UNITED STATES PATENTIOFFICE.

JAMES E. REID, OF MOORE STOWN, NEW JERSEY.

AIR QOMPRESSOR FOR DENTAL AND OTHER PURPOSES.

p r I Application filedNovember'll, 1926-. Serial No. 147,702.

The principal objects of the present invention are, first, to provide a comparatively inexpensive, unitary or self-contained and silent running apparatus adapted to furnish an even or uniform supply of air under pressure and suitable for use by dentists and.

others; second, to obviate the use of separate air tanks and automatlc stoppmg and startmg mechanism; and th1rd,.to provlde a siml0 ple and compact air compressor requiring for bakelite or like material turnably mounted its operation comparatively little power.

Other objects of the invention will appear from the following description at the end of which the invention will be claimed and in the following description reference will be made to the embodiment of. the invention selected for illustration in the accompanying drawings forming part hereof and in which Figure 1 is an elevational view of an air compressor embodying features of the invention.

v Figure 2 is a central sectional elevation of the right-hand end of the structure shown in Figure 1, and

Figure 8 is a sectional view taken on the line 3-3 of Figure 2.

ltn the drawings 1 is a generally cylindrical casing provided, internally with a closed annular air chamber 2, Figure 2, dividing it into motor and pump chambers 3 and 4, and providing an opening 5 for the passage of the motor shaft 6. This casing is shown as mounted upon a stand 7 and afoot 8, and is provided with a handle 9 so that itis selfcontained and portable as a unit. The diam,- eter of,the motor chamber is shown as larger than the diameter of the pump chamber and the difference in diameters is accommodated by the swell or bulge in the outside wall of the air chamber. There is an electric motor arranged in the motor chamber and with the exception of-its shaft 6 and current connectionslO its parts are not shown because its construction is too well understood to require illustration or description. The motor shaft Sextends through the opening5 and projects into the pump chamber 4 which is shown as closed by a plate 11. There are a plurality of radially disposed pump cylinders 12 opening through the cylindrical wall 13 of the pump chamber, and the closed intake ends of these cylinders proj ect beyond thewall 13 and ,are provided with check valves and air radiating -from the opening 5 andarranged "intake fittings 14. '15 are crossheadguides in the pump chamber 4, and at the outside, of

one face of the air chamber 2. There is acrossltead guide for each pump cylinder. 16

generally is an eccentric mounted on the motor shaft 6, or more accurately on' the end thereof, and it is located in the pump chamber and overlies the crosshead guides --.15. This eccentric in the interest of silent running and small power consumption may well be made of a disc or roller 33' of hard fiber,

springs also operate to restore a part of the energy expended in compressing them.

There are air connections 22 from the cylinders 12 to the air chamber 2, and there is an air oiftake 23 from the air chamber2 to the coupling 24 to which may be applied a hose for delivering the air wherever it may be requlred, for example, to a dentists instrument.

.Air is taken into the cylinders by openings at 25 having check valves 26,- Figure 2, and is delivered under pressure fromthe cylinders past the check valves 27, Figure 2. 28is an oil inlet, and 29 is an oil distributor attached to the end of the shaft 6, and taking oil from the reservoir 34.

The motor is directly connected withou the intervention of gearing, and the pump pistons and piston rods are rigidly connected, and the springs hold the flat faces 20 up to the disc 33 of bakelite or like material so that the machine runs silently. The supply of air is uniform because of the plurality of pumping cylinders. The device is compact and small and portable, while eflicient and simple and free from complications in both construction and operation. Moreover the casing may consist of a single casting in which case the core for the air chamber 2 mav be removed through the pluggedopenings 30, and the other parts are simple and easily constructed andmachined. The cap 31 serves to close the end of the, motor chamber so that the casing is substantially closed.

It will be obvious to those skilled in the art that modifications may be made in details of construction and arrangement and in matters of mere form without departing from the spirit of the invention which is not lim-.,

and providing an opening for the passage of a motor shaft, a motor arranged in the motor chamber and having its shaft extending through said opening and into the pump chamber, aplurality of radially disposed immovable pump cylinders opening through the cylindrical Wall of the pump chamber,

crosshead guides radiating from said opening and arranged in the pump chamber and at the outside of one face of the air chamber, a crank pin, on the motor shaft and in K the pump chamber, a disk onithe crank pin,

pump plungers having rigidly connected rods provided with c rossheads working in said guides and riding on the-disk, springs pressing the rods into following relation with the eccentric, valved pipe connections from the cylinders to the air chamber, and

an air ofltake pipe from the air chamber.

2. In an air compressor the combination of a cylindrical casing, a closed annular air chamber dividing the casing into motor and pump chambers and providingan opening be- ,tween them, a motor shaft projecting from the motor'chamber through said opening into the pump chamber, radially disposed fixed pump cylinders opening through the cylindrical wall ofthe pump chamber and havingtheir closed ends projecting beyond the same,

ypump plungers provided with rigidly connected rods, a crank pin, on the motorshaft,

a disk'on the crank pin, for operating said rods in one direction, springs for operating the rods in the other direction, crossheads 4 and crosshead guides for the rods, and air connections arranged outside of the casing, substantially as described.

3. In an, air compressor the combination of a generally cylindrical closed'casing provided internally with a closedannular air chamber dividingit into motor and pump chambers and providing an opening for the passage of a motor shaft, a motor arranged in the'motor chamber and having its shaft extending through said opening and into the pump chamber, a plurality of radially dis-' posed fixed pump" cylinders opening through the cylindrical wall of the pump chamber, crosshead guides radiating from said opening and arranged in the pump chamber and at the outside of one face of the air chamber, an eccentric pin on the end of the motor shaft and in'the pump chamber, a disc revolubly mounted on said pin, pump plungers having rigidly connected rods provided with crossheads working in said guides and with flat faces riding on the disc, springs pressing the flat faces into following relation with the disc, valved pipe connections from the cylinders to the air chamber, and an air offtake pipe from the air chamber.

4. In an air compressor the combination of a driving shaft, a series ofopen ended fixed cylinders radially disposed in respect to the shaft with their 0 en ends confrontingthe J shaft, a'pin eccentrically mounted on the end ofthe driving shaft, 'adisc turnably mounted on the pin, plungers provided with rigidly connected spring pressed rods having flat faces riding on the rim of the disc, and crossheads and crosshead guidesarranged in pro'ximity with said flat faces.

- JAMES E REID. 

